The countdown is on as the Vikings prepare to report to training camp at Minnesota State on Thursday and then start practicing under new coach Mike Zimmer on Friday.

Each day this week at 10 a.m. on the "Mackey & Judd" show we are going to examine different topics involving the Vikings, ending with a prediction of the team's record and finish in the NFC North on Friday.

We started Monday with the three areas we're most curious about entering camp.

Zulgad

Expanded role for All Day? Long-held beliefs about Adrian Peterson include the fact that while he is one of the best running backs of all-time, his game leaves something to be desired when it comes to catching passes or staying in the backfield to pass protect. This is especially true in the latter category.

Well, we're about to find out if these assumptions are true or if Peterson never has been used to his full potential since being taken in the first round of the 2007 draft.

Veteran offensive coordinator Norv Turner, entering his first year with the Vikings, made it clear this offseason that he thinks he can get plenty out of Peterson and that isn't just confined to the running game.

Turner long has been big on having his running back catch passes - Peterson caught a career-high 43 in 2009 from Brett Favre -- and he expressed confidence during an interview on 1500 ESPN in recent months that if Peterson was used in the proper manner in pass protection he wouldn't automatically have to be removed from games on third down.

Considering Peterson will turn 30 next March, finding a way to get him into the open field to catch the ball and avoid punishment at the line of scrimmage makes perfect sense.

That's provided he's better at it than many of us previously thought.

Solution in the middle? Jasper Brinkley returned to the Vikings as a free agent this offseason after one year with the Arizona Cardinals.

A fifth-round pick by the Vikings in 2009 out of South Carolina, Brinkley is expected to be the starting middle linebacker in Zimmer's base defense.

Brinkley was a poor fit for the team's Tampa-2 scheme because he simply wasn't good in pass coverage. What Brinkley is effective at is playing downhill and knocking the stuffing out of running backs.

It remains to be seen if Brinkley will be successful in Zimmer's defense, but given the fact the Vikings didn't aggressively go after another middle linebacker in free agency, the assumption is that Zimmer likes Brinkley or has something else up his sleeve.

It will be interesting to see how much Brinkley plays, even if he does start, because the Vikings could spend much of their time in nickel with Chad Greenway playing in the middle.

Barr examine: There was grumbling when the Vikings selected Anthony Barr with the ninth-overall pick in the draft last May based on the fact many wondered if the outside linebacker should have gone that high.

But that came from fans trying to project Barr into the Tampa-2 scheme. Zimmer's defense will be far more creative and simply calling Barr an outside linebacker would be selling him short.

In one minicamp practice, Barr lined up in a 4-point stance at Jared Allen's old spot on the right end on one play and later was standing up at the line of scrimmage as a rush linebacker.

The Vikings defense promises to be much more creative under Zimmer and Barr moving around to different spots will be a key to that creativity.

Mackey

Catching passes All Day? I, too, am interested in Peterson's role. More specifically, I'm curious to see how many passes he will catch this upcoming season, and I think his usage in training camp will provide some foreshadowing.

Norv Turner's offenses historically have running backs who rack up a ton of receptions and yardage out of the backfield. In Turner's first year in San Diego, Ladainian Tomlinson caught 60 passes for 475 yards. LaMont Jordan caught 70 passes for 563 yards under Turner in 2005. Larry Centers caught 69 for 544 under Turner in 1999. Frank Gore caught 61 for 485 in 2006. Ricky Williams once caught 50 passes under Turner.

Peterson's career high in receptions is 43 in 2009. It's possible he is what he is - a run-first back who will never be a factor in the passing game. But I expect Turner and Zimmer to test this theory throughout training camp and preseason.

Are you gellin'? I'm curious to see how quickly Zimmer can get the defense to gel. Implementing a new system and also new personnel (Anthony Barr, Linval Joseph, Captain Munnerlyn) could mean growing pains, but Zimmer turned the Bengals into a perennial top-10 pass defense within two years of his arrival in 2008.

Improving the pass defense is the key to not blowing multiple fourth quarter leads...

How will QB reps be divided? At most, this is a two-quarterback competition in training camp, and ideally the job is Cassel's for most of the season while Teddy Bridgewater soaks everything in from the sideline. At last, that's my opinion as someone who feels like throwing a rookie quarterback in the fire only works A.) If that QB is a trescendent talent like Andrew Luck, which Bridgewater is not (yet), or B.) If that QB is propped up by a really good defense, which Bridgewater is not (yet).

That said, Bridgewater needs reps, and preferably some of those reps will come with the first team offense. Problem is, if Cassel is destined to be the starter, he'll need as many reps with the first team offense as he can get, considering he's working with a new offensive coordinator in a new system. That leaves Bridgewater working with players who aren't Adrian Peterson, Cordarrelle Patterson and Greg Jennings.

My guess is Cassel will take the vast majority of snaps with the first team offense, Bridgewater will sprinkle in with the first team and work extensively with the backups, and Christian Ponder will handle any leftovers.